legal use of wp and themes

…Jan walks gingerly on the GPL topic…

You may want to give this link a read:

https://www.gnu.org/licenses/gpl-faq.html

WP is released under GPL, so my work ( to custoomize)will be also under GPL, so anyone can use it for free?

You are using someone else’s code (WordPress software) and that code is GPL’ed. So yes, your work with that code is also GPL’ed.

Some of my clients want to put a copyright notice in the footer with their name,etc. It is ok?

They can copyright the content of their blog, but the theme is a derivative of WordPress, which is not theirs to copyright. Lot’s of people place a copyright notice on their site and that’s fine as long as they understand what they are copyrighting.

What about my clients documents- photos, text, etc? I hope these are not considered under the GPL license, because these are property of my clients.

No worries, photos and text that they create are theirs. The GPL applies to the WordPress software.

If I use the default theme there is necessary a footer link to the author of the theme?

With the default theme, the link is not a requirement. It would be nice, but placing that link is optional.

usefull and prompt answer, thank you, Dembowski.

..so how can people sell wordpress themes then? Is that not a derivative of wordpress? These themes certainly don’t have a GPL license. Take Thesis or WP Remix for example.

What is your take on that? Not picking, I’m genuinely interested.

interesting point

…Jan looks around, checks for land mines, asks himself “what would elpie do?”…

This is usually best discussed at https://www.wptavern.com/forum/ but here goes anyway…

The GPL does not prohibit selling your work. It does prohibit applying restrictions on the distribution of that work. So if you create a WordPress theme, it’s automatically GPL’ed since it is a derivative of other GPL’ed software.

You can still sell your work but you cannot restrict the recipient from viewing the source, modifying the source, or prevent them from distributing the work. That’s what the GPL is all about, the free exchange of software.

There are many companies that sell WordPress themes and keep to the GPL. My favorite examples are https://woothemes.com/ and https://www.studiopress.com/ but there are others.

Exhaustive explanation!
Thanks again, Jan

You can still sell your work but you cannot restrict the recipient from viewing the source, modifying the source, or prevent them from distributing the work.

Jan, I know you are very familiarized with GPL, but maybe we should clarify that GPL doesn’t mean that “we MUST distribute our code”.

Themes are GPL, too

As Matt said once:

the GPL allows for choice: it doesn’t force you to distribute the changes to your code, but if you do, you must aside by the GPL, and if you do with binary software you MUST give them source code too.

This is not entirely the case since we are not handling with “binary software”.

But with themes one question remains: what part of your theme is GPL applied? Simple answer: Just the source code and the content rendered by the WP mechanism.

In practice, you can still work for your clients with WordPress since you follow these rules:

1. Make your custom themes GPL
2. For artwork, images, CSS, canvas, content, texts and other stuff not rendered directally by the WP engine apply a proprietary notice with restrictions.

Just one note about copyrights: the copyright notice doens’t mean that your work is proprietary, it just informs the user that the work has a owner and have applied one or more licenses.

Therefore, in practice your works are saved from (re)use if you apply a notice of licensing the Theme as GPL and your artwork, content and CSSes not rendered by any GPLed mechanism as proprietary.